The present invention generally relates to processes and apparatus for making disposable absorbent articles, and particularly to processes and apparatus for making disposable absorbent articles having registered components.
Various products are fabricated in a continuous production line by the sequential addition of components to previously supplied components. This is particularly advantageous when one or more of the components can be supplied in the form of a single continuous layer. For example, in the formation of disposable absorbent articles, such as training pants, diapers, incontinence articles, feminine care products, or the like, a layer is normally supplied at a point in the fabrication line in the form of a continuous roll, and absorbent pads, waist elastic bands, leg elastic bands, stretchable side panels, and/or other elements or components can be individually, separately supplied at different points in the fabrication line as discrete objects to that layer.
Various methods and apparatus are available for bringing these individual, separate components of a single product together so that the components in the composite product are in a desired relation with respect to each other. In bringing these individual, separate components properly together, various known methods and apparatus are used to note the position of a particular component, and then to adjust the placement of subsequent components in order to properly position them.
One problem with current methods and apparatus is that they do not provide an adequate means for registering two continuously moving layers, and particularly when one of the layers has a pre-printed or pre-positioned component or the like that is to be registered with a pre-printed or pre-positioned component or the like on the other of the layers during the manufacture of a plurality of products having a desired registration of components.